Meditation and relaxation-based interventions are becoming more widely accepted and used in clinical settings in part because of their low cost, low risk and proven effectiveness as a complementary intervention in a wide range of diseases. Practice of meditation induces the relaxation response, which is a set of integrated physiologic changes opposite of the stress response. Despite the success and growing use of relaxation response based treatments, few studies have addressed the basic mechanism by which these treatments work. As stated in the National Center for Complementary and Alternative Medicine?s Five- Year Strategic Plan, "is it crucial to rigorously evaluate widely-used CAM treatments" and to "elucidate basic mechanisms" of CAM modalities. The primary goal of this Mentored Scientist Development Award is to use fMRI to define the neural mechanisms underlying the meditative state, differentiate this state from three control states, and then determine how specific neurological changes during meditation modulate autonomic function. Such knowledge could be useful for identifying new medical applications for this intervention, including perhaps, preventative interventions. An integrated series of studies is planned with the following goals: 1) Identify brain loci that are active during meditation and differentiate the pattern of activation from simple rest or mantra-like control states. 2) Define the effects of meditation on global cerebral blood flow and differentiate these from the effects of slow breathing. 3) Integrate fMRI, MEG and EEG data to create high spatial and temporal resolution maps of neural activity during meditation. Determine temporal order of neural activity relative to cardiorespiratory events, to identify loci modulating autonomic function during meditation. The candidate proposes to seek training in: 1) Physiology, including the analysis of complex physiological signals and how to use these data sets to interrogate fMRI data 2) Statistical approaches to functional imaging 3) MR imaging and analysis 4) Neurobiology and neuroanatomy 5) Meditation and the relaxation response.